This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall objective of this project is to explore the potential role of inflammation and oxidative stress in modulating endothelial function among obese African American women. Although the association between obesity and impaired endothelial function is well established, the exact mechanism of this association remains unclear. We will examine the impact of obesity-related inflammation and oxidative stress, on circulating levels of endothelial progenitor cells. Exciting new research in regenerative medicine has identified bone marrowderived endothelial progenitor cells that are involved in vessel repair. Most recently, cardiovascular risk factors have been correlated with decreased numbers of circulating endothelial progenitor cells (EPCs), accelerated EPC apoptosis, impairment of vessel forming capacity and endothelial dysfunction. The proposed study relies on the fact that obesity represents a pre-clinical state of vascular pathology, therefore, it is a unique model that can be used to explore the role of these EPCs in the impairment of endothelial function of obesity. Recognizing the complexity of physiological interactions that determine the ultimate state of the endothelium, we propose to probe the mechanistic basis of the relationships between obesity and endothelial function by incorporating a diet intervention which comprises a nutrient composition that is known to augment antioxidant capacity while providing favorable lipid profiles and glucose tolerance. Long term, this should improve our understanding of the basis for the relationship of obesity to vascular disease and may help in the design of dietary interventions in these high-risk individuals.